[Experimental study on the optimal potassium concentration in the cardioplegic solution].

Area of Science:

• Cardiology
• Biochemistry

Context:

• Potassium cardioplegic solution is crucial for myocardial protection during cardiac surgery.
• Controversy exists regarding optimal potassium levels and perfusion methods.

Purpose:

• To determine the optimal potassium concentration in cardioplegic solution for myocardial protection.
• To evaluate the effect of hypothermia on optimal potassium levels.

Summary:

• Isolated rat hearts were preserved under normothermic (37°C) and hypothermic (4°C) conditions with varying potassium concentrations (15-100 mEq/L).
• Hemodynamic indices were compared to baseline after 30 minutes of preservation.
• A potassium concentration of 40 mEq/L demonstrated the best myocardial protection under normothermic conditions.

Impact:

• Identifies an optimal potassium concentration (40 mEq/L) for myocardial protection.
• Establishes a safe potassium range (25-60 mEq/L) for profound hypothermic preservation.
• Provides evidence-based recommendations for optimizing cardioplegic solutions.